（1）产生20个1~200的随机整数，并依次保存到带头结点的单链表中。（2）计算单链表的长度，并将结果存放在头结点的数据域中，然后输出单链表的所有元素。（3）从单链表中删除与给定值x相等的所有结点，并输出结果。

（1）在Python中，你可以使用random库生成随机整数并创建链表。首先，创建一个Node类作为链表节点，然后创建链表类ListNode用于操作。以下是一个示例：

import random

class Node:
    def __init__(self, value=0):
        self.value = value
        self.next = None

class ListNode:
    def __init__(self):
        self.head = Node()

    def append(self, num):
        if not self.head.next:
            self.head.next = Node(num)
        else:
            current = self.head
            while current.next:
                current = current.next
            current.next = Node(num)

# 生成随机整数并添加到链表
nums = [random.randint(1, 200) for _ in range(20)]
for num in nums:
    linked_list = ListNode()
    linked_list.append(num)

（2）接下来计算链表长度，并更新头节点的数据域：

def length(head):
    count = 0
    current = head.next
    while current:
        count += 1
        current = current.next
    head.value = count
    return count

length(linked_list.head)

# 输出所有元素
current = linked_list.head.next
while current:
    print(current.value)
    current = current.next

（3）最后删除链表中等于给定值x的节点：

def delete_nodes(x, head):
    if not head or not head.next:
        return head
    
    current = head
    while current and current.value != x:
        prev = current
        current = current.next
        
    if current and current.value == x:
        if current == head:
            head = head.next
        else:
            prev.next = current.next
            
    return head

# 删除特定值的节点
delete_nodes(x, linked_list.head)

# 再次输出链表
current = linked_list.head.next
while current:
    print(current.value)
    current = current.next